1. Field of the Invention
The present invention relates, in general, to high pressure fuel supply pumps for supplying injectors of internal combustion engines with high pressure fuel and, in particular, to a drive mechanism for a plunger that is slidingly fitted in a cylinder of the pump and that makes a reciprocating motion therein.
Specifically, the present invention relates to an arrangement of a drive mechanism for translating rotation of a cam to a corresponding reciprocating motion of a plunger, the drive mechanism including a tappet having a first surface on which a front surface of the cam abuts and a second surface on which a lower end of the plunger abuts and a spring for pushing the plunger back from a top dead center position to a bottom dead center position, a force of the spring being transmitted to the plunger via a retainer.
2. Description of Related Art
A drive mechanism for a plunger of a high pressure fuel supply pump as disclosed, for example, in JP-2005-514557-T and JP-2001-295754-A is arranged so that a force of a return spring presses the plunger against a surface of a tappet via a retainer at a bottom dead center position of the plunger.